What is the difference between an octopus and a squid? The two cephalopods appear to be similar and are often confused with each other. After all, they both possess eight arms, high levels of intelligence, and can push ink out of their ink sacs and disguise their bodies to avoid prey. However, despite this similarity, octopuses and squid differ in several important areas. If you’re skeptical, just order a plate of squid or octopus tentacles at the restaurant. Soon enough, you will realize that these ancient sea-dwelling creatures have unique qualities that set them apart from each other. In this article, we’ll compare octopus and squid and discuss 8 key differences that you can use to tell them apart. We’ll also answer a few frequently asked questions about octopuses and squid.
Comparison of octopus and squid
| Octopus | Squid | |
| The size | 1 “to 30 feet 1 gram to 600 pounds |
0.5 inches to 43 feet Less than a gram per ton |
| Robe and head | Round robe and head | Triangular head and mantle Fins along the mantle The highway is called “feather” |
| Habitat | Seabed, coral reefs, coastlines and deep ocean | Open ocean and deep ocean |
| Hands | 8 hands covered with suction cups No hooks and rings on suction cups Can be used for locomotion |
Two retractable tentacles to capture prey Hooks and suction cups or suction cups |
| Diet and feeding | Crustaceans, worms, puppies, molluscs, shrimps, fish Paralyzing or toxic saliva dissolves food |
Shrimp and fish Catch food with tentacles and hold with your hands Eat your booty in chunks |
| Life span | 1-3 years old Up to 5 years |
1 to 5 years old Up to 15 years old |
| Socialization | Single if not mating Can live in high density Sometimes hunt with other species, usually fish. |
Can use light and color change to communicate Live alone or in schools Some hunt together |
| Reproduction | Special hands, called hectocotyl, carry sperm into the cavity of the woman’s mantle. Females guard the eggs in the den |
Mate in large groups Attach eggs to rocks or algae, or let the eggs float freely Don’t guard the eggs |
8 key differences between octopus and squid
Octopus and squid: size
In general, the difference in size between octopus and squid is small. However, in extreme cases, there are more differences between squid species. The smallest octopus, Octopus wolfi, is just under 1 inch long and weighs about a gram. Meanwhile, the giant Pacific octopus can reach 30 feet in length and nearly 600 pounds. Extremely extreme, if we compare these figures with the smallest and largest squid, the difference will soon become apparent. For example, the Thai bobtail squid is the smallest known cephalopod molluscs. It is less than half an inch long and weighs less than a gram. On the other hand, the giant squid can reach 43 feet in length and weigh over a ton. Basically, while octopuses grow larger than squid on average, squid has a much larger range of sizes.
Octopus and squid: mantle and head
Both octopuses and squids are animals with head legs, most of their vital organs are enclosed in a mantle. However, their robes and head look completely different when compared side by side. Octopuses have a round back and head and appear rather bulging. Their robes come in a variety of colors and patterns, although many species use camouflage to match their habitat. With the exception of Dumbo the octopus, octopuses have no fins on their mantle. On the other hand, the squid mantle is triangular in shape. Unlike octopuses, tiny fins appear on the fins on either side of the mantle, which they use for movement and navigation. the patterns and colors of the squid should appear more subdued, although they can also camouflage when threatened.
Octopus and squid: habitat
There are several differences in the preferred habitat of octopuses and squid. Generally speaking, octopuses live near the seabed. They build their lairs on coral reefs, near the shores and on the ocean floor, both at great and deep depths. However, some octopus species spend most of their time in the open ocean, but they are the exception to the rule. On the other hand, squid mostly live in the open ocean. Since they don’t build dens like octopuses do, they don’t need to live on the ocean floor. They are often found both near the surface and at depths.
Octopus and Squid: Weapons
Another difference between an octopus and a squid is their hands. While they seem similar at first, if you look closely, some differences will soon become apparent. On average, octopuses have one or two rows of suckers on their hands. However, they do not develop suckers or hooks at the ends of their arms. They use their hands to grab and hold prey and as a rudimentary form of locomotion when traveling on the seabed. Meanwhile, squid may have suckers or suckers on their hands. In addition, in some species, the arms end in small hooks, which likely evolved to help squid hold wriggling prey. However, the biggest difference between the two is that squid also have two long tentacles. Squids use their tentacles to grab prey while they manipulate their eight arms to hold on to food while feeding.
Octopus and squid: diet and feeding
As mentioned earlier, octopuses use their hands to catch and hold prey, while squids use their tentacles to grab prey and their hands to hold prey. However, there are several other differences between the diet and feeding behavior of octopuses and squid. Octopuses primarily feed on crustaceans such as crabs, shellfish and calves, although some of the larger species also feed on fish and shrimp. Once they catch the prey, they often drag it back to the den. There, they inject poisonous saliva into their food using their hard beaks. This saliva paralyzes the prey and dissolves the hard outer shell, which allows the octopus to feed on the soft inner flesh. On the other hand, squid usually feed on shrimp and small fish. Instead of relying on their saliva to dissolve their prey, they simply tear apart the flesh of their food and rip out chunks with their powerful beaks.
Octopus and squid: lifespan
Depending on the species, the lifespan of octopus and squid can vary significantly. On average, most octopuses and squids die shortly after mating, which means that their lifespan only lasts until they reach puberty and have a chance to mate. However, it seems that squid live longer in the wild. The average lifespan of an octopus is 1 to 3 years. However, some octopuses live only 6 months, while others can live up to 5 years. Meanwhile, most squid live between 1 and 5 years. Although some of them live only 9 months, reports show that some species of squid can live for almost 15 years.
Octopus and squid: socialization
For many years, scientists did not consider octopuses and squids to be particularly friendly animals. This makes sense given that they usually live in solitude, except during the mating season. However, recent evidence suggests that these early guesses only told part of the story. It is true that most octopuses tend to live in solitude. However, some species will live in areas with a high density of other octopuses. In addition, some species will share a den with other animals, while others will hunt with fish together. On the other hand, squid seem to be much more social than originally thought. While some squid live in solitude, others prefer to live in packs, such as reef squid. Plus, research shows that other squid can talk to each other. For example, reports show that Humboldt squids use color and light changes to communicate with each other.
Octopus and squid: reproduction
When it comes to deciding which species is the best parent, there is no competition between octopus and squid. Octopuses reproduce using a special hand used by males called a hectocotyl, which carries the male’s sperm into the cavity of the female’s mantle to fertilize eggs. The females then lay eggs in their dens and aggressively guard their offspring until they are born. Some females even go as far as to build walls to keep out potential predators. On the other hand, squid mate in large groups, either through hectocotyl or by a method known as head-to-head mating. Instead of guarding their eggs, females simply attach their eggs to rocks or algae. Some species don’t even bother to attach their eggs to a hard surface and just leave their eggs floating in the open ocean until they hatch.
Frequently asked questions about octopus and squid
How many species of squid and octopus are there?
There are over 300 recognized species of squid and 300 species of octopus.
How do squids and octopuses protect themselves from predators?
Squids and octopuses have developed several defense mechanisms to help protect themselves from predators. When threatened, they can fire ink from their ink sac to distract attackers. In addition, many species can disguise their bodies to blend in with their environment, which helps them avoid potential threats.